Throttle system

ABSTRACT

Disclosed is a throttle quadrant arrangement having a throttle lever which is independently mechanically connected to different Rotary Variable Differential Transformers (RVDTs). A friction lever selectively creates and releases friction from the throttle lever to enable it to be selectively positioned. The system is configured such that the mechanical connections existing between the throttle lever and the RVDTs are shielded from the friction created by the friction lever.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/776,732 filed Dec. 7, 2018, the entire contents ofwhich are hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field

The disclosed embodiments relate generally to the field of throttlequadrant systems for aircraft. More specifically, the embodiments relateto the prevention of mechanical failures existing between the throttleand engine of the aircraft.

2. Description of the Related Art

Throttle arrangements have been used in aircraft. Some throttles operateby converting mechanical activation from the throttle lever into digitalinformation that is received by a controller, which takes the digitalinformation received and in turn, changes an aircraft parameter (e.g.,engine speed), in response.

FIG. 1 discloses shows a prior art throttle system arrangement 10 whichmight be employed in a typical two-engine jet-propelled aircraft havingengines on both sides of the aircraft. In this sort of arrangement, athrottle control block 12 includes first and second sticks, 14 and 16which are located in close proximity to one another so that they can beeasily moved together. But the two sticks are also independent so thateach can be moved to different settings. Each stick is configured tooperate one of two turbine engines, 18 and 20. The rotation of each ofsticks 14 and 16 is mechanically imparted into pairs Rotary VariableDifferential Transformers (RVDTs). RVDTs, as is known in the art, takemechanical rotation, and based on angular displacement, transmit signalsso that the extent of displacement can be used by digitally-basedelectronic systems existing in the aircraft. Referring to FIG. 1, firststick 14 is mechanically connected to each of the RVDTs in a pair 22 viaa common mechanical linking system (not shown). Two RVDTs are usedinstead of one in order to meet redundancy requirements. The mechanicalrotation is translated by the RVDTs 22 into digital signals which arereceived into a Full Authority Digital Engine Control (FADEC) system 24.A FADEC includes a computer and operates as an engine control unit.Normally the FADEC controls most or all aspects performance for theturbine engines. For example, the correct fuel flow and power levels forthe engine are determined by the FADEC. In the FIG. 1 conventionalsystem, a FADEC 24 is used to operate a first 26 of two engines. Theelectronic signals emitted from the RVDT pair 22 are interpreted by theFADEC 24, and used to automatically increase or decrease the speed ofthe first turbine engine 26 through varying fuel rate as well asnumerous other variables.

The system also includes a stick 16 to control engine 20. Morespecifically, stick 16 is linked mechanically to a second RVDT pair 26.The pair feeds signals into a FADEC 28, and then FADEC 28 controls thefuel flow, and thus the speed of engine 20.

FIG. 2 shows a second prior art throttle system 11 used on asingle-engine turboprop aircraft. Those skilled in the art willrecognize that a turboprop engine is one where a turbine engine 21drives an aircraft propeller 19. This conventional system utilizes ablock 13 including two levers 15 and 17. Lever 15 controls the pitch ofthe turboprop, whereas second lever 17 controls turbine speed. Byindependently moving levers 15 and 17, thrust output is controlled. Thepitch of the propeller and the speed of the turbine are controlled bytwo separate mechanical systems.

SUMMARY

A throttle system for an aircraft is disclosed. In some embodiments thesystem has a throttle lever. The lever is mechanically connected tofirst and second mechanical-rotation to electronic conversion devices,each of the first and second conversion devices being adapted to receivemechanical angular rotation. The devices emit first and secondelectronic signals, each indicating a rotation extent. The system alsoincludes an automated control system configured to use either of thefirst and second electronic signals to control the operation of anengine. In some versions the conversion devices can be Rotary VariableDifferential Transformers (RVDTs).

In some embodiments, the electronic signals are utilized by theautomated control system to control the speed of a turbine engine, apiston engine, or the pitch of a propeller and also the speed of anengine used to drive the propeller.

A linkage system can include first and second mechanical linking systemsconnecting the throttle lever to the first and second conversion devicesand upon a failure in the first linking system, the second mechanicallinking system will remain operational. In some embodiments, a firstdesigned point of failure is established in the first mechanical linkingsystem, the first designed point of failure creating a disengagingbreaking upon encountering a first abnormal resistance force, the firstdesigned point of failure avoiding interference in the mechanicaloperation of the second mechanical linking system. Similarly, a seconddesigned point of failure is established in the second mechanicallinking system, the second designed point of failure creating adisengaging breaking upon encountering a second abnormal resistanceforce, the second designed point of failure avoiding interference in themechanical operation of the first mechanical linking system.

In some versions the point of failure is established using a shearablefastener establishing a point of connection between two structuralcomponents in the linking system as a weakest point upon theencountering of a resistance force. Optionally, the point of failure isestablished by incorporating frangible links into the first and secondmechanical linking systems.

In other embodiments the point of failure in the first mechanicallinkage system is established by a spring-driven plunger arrangementincorporated adjacent to a detent formed into a disk-drive leverrotating with the throttle stick, the detent being configured to receivea tip of the plunger, the plunger and detent being designed such thatwhen the first abnormal force of resistance is encountered, a springforce of the ball plunger will be overcome, and the tip rises up out ofthe detent releasing the drive lever. The plunger arrangement can bedesigned according to the formula TSF=F/tan(Ø/2) where TSF is a desiredthreshold side force, F is an end force for a spring in the plunger, andØ is the angle at which a pair of opposing side walls in the detentexist relative to one another.

In other embodiments, the point of failure is established using a firstlinking subsystem including a first disk rotatable about the hub, thefirst disk connected to and driven by the throttle lever to create afirst tangential source of leverage, the first disk using the leverageto drive a first link, the first link being mechanically connected torotate the first conversion device; and a second linking subsystemcomprising a second disk rotatable about the hub, the second diskconnected to and driven by the throttle lever to create a secondtangential lever, the second lever driving a second link connected torotate the second conversion device.

In some embodiments a third linking subsystem including a third rotatingdisk rotatable about the hub, the third disk connected to and driven bythe throttle lever to create a third tangential lever, the third leverdriving a third link connected to rotate a third conversion device, thethird conversion device configured to, upon movements of the throttlelever, transmit a third signal independently usable by the enginecontrol system to increase or decrease speed.

In some embodiments a first drive arm extending outward from the firstdisk, the first drive arm mechanically connected to a first linking arm,the first linking arm mechanically connected to and configured to createrotation in the first conversion device; and a second drive armextending out from the second disk, the second drive arm mechanicallyconnected to a second linking arm, the second linking arm mechanicallyconnected to and configured to create rotation in the second conversiondevice.

The throttle system, in some embodiments, has first and second disks areeach divided into separable halves, a receiving half linked to receiverotation from the throttle lever, and a driving used to mechanicallyimpart rotation into the conversion devices, the separable halves beingsecured together by shear members, the shear members configured to failupon a mechanical jam and release a jammed first or second disk as adriving connection between the throttle lever and the first or secondconversion device.

The conversion devices can be Rotary Variable Differential Transformers(RVDTs). In embodiments, signals from the conversion devices areredundant, the engine control system being operable on either.

In yet other embodiments, disclosed is a system for operating anaircraft having a throttle system including a single throttle lever, thelever being mechanically connected to a plurality of conversion devices,each of the conversion devices adapted to receive mechanical angularrotation upon operation of the throttle lever, and emit an electronicsignal indicative of a rotation extent. Additionally, an independentmechanical arrangement can exist between the throttle lever and eachconversion device, each mechanical arrangement being designed such thatinoperability of one independent mechanical arrangement will not defeatoperability of at least one other mechanical arrangement.

In other embodiments, a friction-creating lever operated along with thethrottle lever, the friction-creating lever selectively applying lateralcompression to the throttle lever enabling the compression lever to beselectively secured into a plurality of different positions; and themechanical arrangements between the throttle lever and each conversiondevice being configured such that they are not exempted from the lateralcompression applied to the throttle lever. In some arrangements, acontrol system is configured to: (i) receive electrical outputs fromeach of the conversion devices; (ii) detect if the signal readings fromany of the conversion devices are outside of a range, the rangeindicating operability; and (iii) use a signal reading from one or moreof a still-properly-operating conversion device, or an average readingof a plurality of devices as a thrust indication.

Processes for evaluating the viability of RVDTs and other conversiondevices are also disclosed. For example, a process is disclosed formanaging signals from a plurality of conversion devices in an aircraft,each conversion device being configured to receive an input from amechanical system, and create an electrical signal output to an enginecontrol system. In embodiments, the process includes continually readingelectrical outputs from first, second, and third conversion devices inthe plurality; determining if the signal readings from any of the first,second, and third conversion devices are outside of a predeterminedrange, inclusion in the range indicating operability; and establishing athrust commands in the engine control system based on the inclusion inthe range of each of the signals received from the first, second, andthird conversion devices.

In some versions the process involves using a reading from any one ofthe first, second, and third conversion devices in the engine controlsystem to establish a thrust command if all of the first, second, andthird conversion devices are within the predetermined range. Wherereadings from the first and second conversion devices are inside of therange, and the reading from the third conversion device is outside ofthe range, the system can use a reading from one or both of the firstand second conversion devices in the engine control unit as a thrustcommand. Sometimes the reading from the first conversion device is usedalone in the engine control unit as a thrust command, and sometimes thisis done by averaging the readings derived from both the first and seconddevices to comprise a thrust command utilized by the engine controlunit. In some embodiments, a warning is transmitted to an alert systemon the aircraft.

In some embodiments where: (i) only one of the readings from the first,second, and third conversion devices is within the predetermined range,or (ii) none of the readings from the first and second conversiondevices are inside of the range, using a default process to establishthrust commands in the engine control system. Since the conversiondevices are thus unreliable, the system can use an idle power setting asthe default setting if the aircraft is on the ground, or a cruise powersetting if the aircraft is in the air. Also, due to urgency, a shortterm warning can be sent to an alert system on the aircraft.

A throttle-control system for aircraft is disclosed. In the system, athrottle lever mechanically connected to a first, second, and thirdconversion device; the first, second, and third conversion devicesconfigured to receive mechanical rotation created by the throttle lever,and generate first, second, and third signals, respectively; an enginecontrol system adapted to maintain a thrust output, the engine controlsystem including a processing component; the processing componentconfigured to: reading electrical outputs from first, second, and thirdconversion devices; determine if the signal readings from any of thefirst, second, and third conversion devices are outside of apredetermined range, an inclusion in the range indicating operability;and establish a thrust output based upon the consideration of theinclusion of each of the signals received from the first, second, andthird conversion devices inside the range.

In embodiments, the processing component further configured to dodifferent things. For example, use a reading from one or both of thefirst and second conversion devices in the engine control unit as athrust command where readings from the first and second conversiondevices are inside of the range, and the reading from the thirdconversion device is outside of the range, use the reading from thefirst conversion device alone in the engine control unit as a thrustcommand, or average the readings derived from both the first and seconddevices to comprise a thrust command utilized by the engine controlunit. Additionally, the processing component can be configured toactivate a default process to establish thrust commands in the enginecontrol system when: (i) only one of the readings from the first,second, and third conversion devices is within the predetermined range,or (ii) none of the readings from the first and second conversiondevices are inside of the range, the default process being using an idlepower setting as the default setting if the aircraft is on the ground,or using a cruise power setting if the aircraft is in the air. In thismode, a short term warning can be transmitted to an alert system on theaircraft.

Embodiments also involve isolating the throttle from the friction leverarrangement on the throttle quadrant. For example, a throttle system isdisclosed including a throttle lever configured to rotate around a hub;a linking system, the linking system mechanically imparting rotationimplemented by the throttle lever to an engine control system, thethrottle lever rotating about a hub; a friction adjustment leverconfigured to rotate about the hub, the friction adjustment leverconfigured such that movement in a first direction of rotation aroundthe hub increases friction experienced by the throttle lever, andmovement in a second direction of rotation around the hub decreasesfriction experienced by the throttle; and a friction-exemptingsubsystem, the subsystem preventing the friction created by the frictionadjustment lever to be experienced by the linking system.

In versions, the linking system includes at least one rotatable diskwhich is mechanically linked to and rotates with the throttle lever, therotating disk driving at least one link to implement rotation into amechanical-to-electrical conversion device, the mechanical-to-electricalconversion device configured to, upon movements of the lever, transmitsignals indicating an extent of displacement which are used by theengine control system to increase or decrease speed. The frictionadjustment lever in some embodiments creates friction using a camarrangement, the cam arrangement creating compression between thefriction adjustment lever and the throttle lever. More specifically, therotating disk can be maintained in mechanical independence from thecompression created by the cam arrangement by at least one spacingdevice, the spacing device bearing at least some of the compressioncreated by the cam arrangement such that the rotating disk is unaffectedby the friction. In embodiments, the hub is stationary and is securedbetween two opposing side plates.

In more specific embodiments, the cam arrangement includes a first camportion located on a disk portion at the bottom of the friction lever,the first cam portion rotating against a second reciprocating camportion located on a relatively stationary friction disk located inbetween the disk portion at the bottom of the friction lever and thethrottle lever. The relatively stationary friction disk is preventedfrom rotation by a friction-disk linking bolt which is secured throughthe opposing side plates.

In embodiments, the friction adjustment lever is configured to loosenthe throttle lever, and secure the throttle lever in place such that apilot does not need to maintain a hand on the throttle lever to maintaina position.

In embodiments, a first linking subsystem including a first rotatingdisk rotatable about the hub, the first disk connected to and driven bythe throttle lever to create a first tangential lever, the first leverdriving a first link connected to rotate a firstmechanical-to-electrical conversion device, the firstmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a first signal indicating a first extentof displacement which is usable by the engine control system to increaseor decrease speed is implemented. Further, a second linking subsystemcomprising a second rotating disk rotatable about the hub, the seconddisk connected to and driven by the throttle lever to create a secondtangential lever, the second lever driving a second link connected torotate a second mechanical-to-electrical conversion device, the secondmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmits a first signal indicating a secondduplicitous extent of displacement which is usable by the engine controlsystem to increase or decrease speed. The friction-exempting subsystem,in some embodiments, exempts the first and second disks from beingsubjected to friction created by the friction lever.

In embodiments, a third linking subsystem includes a third rotating diskrotatable about the hub, the third disk connected to and driven by thethrottle lever to create a third tangential lever, the third leverdriving a third link connected to rotate a thirdmechanical-to-electrical conversion device, the thirdmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a third signal indicating a third extentof displacement which is optionally usable by the engine control systemto increase or decrease speed. In versions, the third signal isredundant of the first and second signals, and the engine control systembeing operable on any of the first, second, or third signals. Thefriction-exempting subsystem can prevent the third disk from beingsubjected to friction created by the friction lever in embodiments.

In some embodiments, a throttle disk formed out of a lower portion ofthe throttle lever to configure the throttle lever to rotate around thehub; first and second apertures formed through the throttle disk toreceive first and second bolts; and the first and second bolts passthrough first and second sleeves, the second and first sleevescomprising the friction-exempting subsystem by bearing compressioncreated by the friction lever, and transmitting the compression to thethrottle disk.

In embodiments, a first linking subsystem and a second linking subsystemin the linking system; the first linking subsystem including a firstrotating disk rotatable about the hub, the first disk connected to anddriven by the throttle lever to create a first tangential lever, thefirst lever driving a first link connected to rotate a firstmechanical-to-electrical conversion device, the firstmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a first signal indicating a first extentof displacement which is usable by the engine control system to increaseor decrease speed. A second linking subsystem comprises a secondrotating disk rotatable about the hub, the second disk connected to anddriven by the throttle lever to create a second tangential lever, thesecond lever driving a second link connected to rotate a secondmechanical-to-electrical conversion device, the secondmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmits a first signal indicating a secondduplicitous extent of displacement which is usable by the engine controlsystem to increase or decrease speed; and a compression disk located onthe hub, the compression disk being connected to the first and secondbolts thus sandwiching the first and second sleeves between thecompression disk and the throttle disk, the first and second disks onthe hub being contained between the compression disk and the throttledisk thus exempting the first and second disks from compression.

Also disclosed is a process for securing a throttle in a plurality ofpositions. The process includes steps of providing a throttle lever on ahub; creating rotation using the throttle lever; tangentially linking aplurality of redundant engine-driving disks on a hub to the throttlelever; configuring each of the engine-driving disks to redundantly linkthe throttle lever to an engine control system; creating compression onthe throttle lever using a friction lever such that the throttle levercan be secured into the plurality of positions; securing theengine-driving disks between a compression-bearing disk on the hub andthe throttle lever; and rigidly spacing apart the compression-bearingdisk from the throttle lever to bear the compression created by thefriction lever and preventing the friction created by the frictionadjustment lever to be experienced by the engine-driving disks.

Also disclosed is a process including the steps of providing a throttlelever on a hub; creating rotation using the throttle lever; tangentiallylinking a plurality of redundant engine-driving disks on a hub to thethrottle lever; configuring each of the engine-driving disks toredundantly link the throttle lever to an engine control system;creating compression on the throttle lever using a friction lever suchthat the throttle lever can be secured into the plurality of positions;securing the engine-driving disks between a compression-bearing disk onthe hub and the throttle lever; rigidly spacing apart thecompression-bearing disk from the throttle lever to bear the compressioncreated by the friction lever and preventing the friction created by thefriction adjustment lever to be experienced by the engine-driving disks.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Illustrative embodiments are described in detail below with reference tothe attached drawing figures, which are incorporated by reference hereinand wherein:

FIG. 1 shows a prior art throttle system arrangement sometimes employedin jet-propelled aircraft;

FIG. 2 shows a prior art throttle system used in most turbopropaircraft;

FIG. 3 shows a system diagram for an embodiment for a system environmentfor a single-stick throttle system like the embodiments describedherein;

FIG. 4 is a perspective view showing a throttle stick embodiment as itappears removed from the control panel in the cockpit of an aircraft;

FIG. 5 is an exploded view showing the detailed components included inthe throttle stick embodiment shown in FIG. 4;

FIG. 6 is an exploded view showing the details of an RVDT subsystemassociated with the throttle stick embodiment in FIG. 4;

FIG. 7 is an exploded view showing the details of a linking armsubsystem associated with the throttle stick embodiment in FIG. 4;

FIG. 8 is a stripped-down perspective view of the throttle stickembodiment of FIG. 4;

FIG. 9 is a perspective view showing the three drive levers used in anembodiment of the system revealing the front of each lever;

FIG. 10 is a perspective view showing the three drive levers from adifferent perspective;

FIG. 11 is a view from the same perspective as in FIG. 9, but with thelevers shown exploded such that fastening mechanisms can be seen indetail;

FIG. 12 is a cross sectional view taken from Section 12-12 in FIG. 9;

FIG. 13 is a cross sectional view taken from Section 13-13 in FIG. 9;

FIG. 14 is a flow diagram showing, for an embodiment, the processesincluded in an RVDT voting process.

FIG. 15 shows a schematic for a system embodiment for an environment inwhich the processes of FIG. 14 might be executed;

FIG. 16 shows an alternative system embodiment to the one shown in FIG.15;

FIG. 17 is a perspective view showing a ball-plunger alternativeembodiment;

FIG. 18 shows a section taken out of a perspective view of theball-plunger arrangement wherein the internals are revealed; and

FIG. 19 shows a cross-sectional view revealing the ball-plunger systemat the pin.

DETAILED DESCRIPTION

Embodiments provide systems and a method for controlling the speed andthrust of aircraft. In embodiments, the aircraft is a turboprop type.Turboprop aircraft have a turbine that is used to drive the aircraftpropeller. In order to manipulate thrust, the pitch of the propellerblades can be adjusted.

High Level Description

The systems and methods of operation disclosed herein, unlikeconventional systems, enable the use of a single throttle lever with acontroller to operate more than one thrust related function on anaircraft. The controller could be an automated engine control system,e.g. a FADEC system. Additionally, the systems and methods enable theoperation of a turboprop with only a single lever.

The single lever throttle quadrant feeds information about throttlelever commands to the controller (e.g., FADEC system). Threemechanical-rotation to electronic-conversion devices, e.g., RVDT's areused to verify throttle the single-lever position, and feed thatinformation to the FADEC. The FADEC determines the correct fuel flow andpower levels for the turbine engine, as well as pitch control for thepropeller. Not only is the use of a single lever/FADEC system unique,the jam protection for a single point failure of the RVDT's is unique aswell.

The unique protection against RVDT jamming is in the lower part of thethrottle quadrant. The disclosed embodiment has three RVDTs connected tothe single stick. The three mechanical linkage systems are eachcompletely independent from each other. Each independent system takesrotation from the stick. The stick rotates the three disk levers (whichrotate about the hub when acted on by the stick). When each disk leveris moved, it drives a link that causes rotation in a drive link, therotation of which is measured by each RVDT. The three disk levers rotatetogether, and each mechanical system from the disk levers to each RVDTis completely mechanically independent. Thus, upon the encountering ofan abnormal amount of resistance force, e.g., if one of these systemsjams, the other two will continue to operate upon the rotation of thestick.

Each RVDT is independently connected by a four-bar linkage to twoindividual plates that rotate on the center hub of the throttle quadrantwhen the throttle lever is moved. The series of plates are rotatablymounted on the hub and connected to the throttle lever by two bolts. Twoplates per RVDT are riveted together to provide a positive connectionbetween the RVDT and the throttle lever. When a RVDT jam occurs, theforce provided by the pilot on the throttle lever will shear the rivetslocated between the two plates of the corresponding RVDT. This causesthe disengagement of the independent mechanical system serving thejammed RVDT, and allows the throttle lever to continue to rotate on thehub with the other two RVDT's, providing commands to the FADEC.

A voting system is used to determine how to read the RVDTs in the eventof some error, e.g., a jam or other fault. The computer system receivesposition readings from all three RVDTs. If one of the three isdifferent, then you use an average of the readings of the other two astrue. More specifically, the process involves looking at the first twoRVDT measurements, then seeing which of these two is the closest to thereading from the third RVDT. Thus, the third RVDT “votes” for thereading that is closest to it.

Historically some throttle arrangements have included the ability toimpose friction on the throttle for desired feel, and more importantlyto give the stick stay-ability in a particular location. This systemprovides means to have a stick-driven RVDT linkage system that is notimpacted at all by increases or decreases indicated by the separatefriction lever.

System Embodiment

FIG. 3 shows an embodiment for a system embodiment 30 which enables theuse of a single throttle lever control block 32, in embodiments, for aturboprop aircraft. As can be seen, the control block 32 includes asingle lever 34 which will be the sole user interface required forcontrolling engine speed, propeller pitch, and thus, thrust. Mechanicalinput is received from lever 34 independently into a first, a second,and a third RVDT, 36, 38, and 40 respectively. Electronic signals fromRVDTs 36, 38, and 40 are fed into a single controller 42. The controller42, in embodiments, can be a FADEC system. Controller 42 has beenconfigured to accommodate both controls relating to the pitch of anaircraft propeller, as well as fuel intake and other control informationnecessary to operate a gas turbine 46.

It should be noted, that the technologies discussed herein could beincorporated into systems involving the control of an automaticallycontrolled piston-engine aircraft (with or without the incorporation ofa FADEC). Further, the system could be implemented on engine-drivenaircraft where pitch-control is not executed. Thus, the disclosuresherein should not be limited only to implementations into turboprops.

The mechanical connections between the single lever 34 and each of theRVDTs are completely independent from one another. For example, (i) amechanical connection 48 between lever 32 and RFDT 36; (ii) a connection50 between lever 32 and RVDT 38; and (iii) a connection 52 between lever34 and RFDT 40; ensures that the other two RVDTs continue to operate asintended even if one of the other systems is jammed or otherwise fails.

The electronic connections (e.g., a signal pathway 54 from RVDT 36; asignal pathway 56 from RVDT 38, and a signal pathway 58 from RVDT 40)are also independent from one another into the controller 42. This meansthat if one RVDT is lost, signals from the other two will still bereceived.

The Throttle Lever in General

Generally, referring to FIG. 4, the system of the disclosed embodimentincludes a throttle lever 102 which extends down through a slot 106created in a cover plate and LED panel assembly 104. A flap-leverassembly 108 also has a lever 109 which extends up through a slot in thecover plate and LED panel 104. The cover plate/LED panel assembly 104has been removed in FIGS. 5, 6, 7, and 8 for the sake of simplicity.Throttle lever 102 is used to create forward or rearward axial rotationabout an axial assembly 110. This axial rotation is used to createelectronic readings by three redundant devices capable of measuringangular displacement, and outputting a signal. In the disclosedembodiment, these three redundant devices include a first RVDT 36, asecond RVDT 38, and a third RVDT 40. Those skilled in the art will befamiliar with RVDTs as being electromechanical transducers that, uponangular displacement of an input shaft, transmit an output voltage whichis proportional to the displacement imposed. This voltage is thenrecognized by a computer supported or other sort of system which usesthe voltage to create some response. In the field of aircraft, theresponse may involve control over the power input of the aircraft. Thesystems herein likely have numerous other applications in thetransportation, gaming and other fields. Thus, the embodiment disclosedshould not be an indication that the concepts are not applicable tonumerous other applications.

Overall Throttle Lever Assembly

The system, except for the flap lever assembly 108, is mostly containedbetween side plates 118 and 120 using bolts. Side plate assembly 118 issubstantially parallel to, displaced from, and opposes a second sideplate assembly 120. The RVDT arrangement is substantially supportedusing a RVDT plate assembly 122. Lever assemblies are rotated about astationary hub 124. These lever assemblies are part of a self-containedassembly that are rotated mechanically by the throttle lever 102. Thefirst, second and third linking arms 270, 272, and 274, respectively,are used to independently drive each of RVDTs 38, 40, and 36respectively, in a four-bar mechanical assembly.

Bolts 126, 128, 130 and 132 each pass through plates 118 and 120 and aresecured by washers and nuts located outside of side plate 120. Bolt 130secures stationary hub 124 and end cap 228 to the outer side plates 118and 120. The friction lever, friction discs, friction cam, nested wavespring, drive spacers, lever assemblies and throttle lever are containedbetween the side plates 118 and 120 and rotate on stationary hub 124.The friction lever rail 138 and throttle lever detent rails 144 and 150are contained between side plates 118 and 120 and held in place bybolts, spacers and nuts.

For example, a bolt 126 passes through hole made through side plate 118,then through a spacer 134, a hole 136 in a first side friction leverrail 138, a spacer 140, a hole 142 in a second throttle lever detentrail 144, a spacer 146, a hole 148 in right throttle lever detent rail150, a spacer 152, a hole 154 in right side plate assembly 120, a washer156 and finally is threaded into a nut 158 complete the containment ofthe plates 118 and 120 between the head and tip of bolt 126.

A bolt 128 passes through a hole 160 in side plate assembly 118, aspacer 162, a hole 164 in friction lever rail 138, a spacer 166, a hole168 in lower part of a first throttle lever detent rail 144, a spacer170, a hole 172 in the lower part of a second throttle lever detent rail150, a spacer 174, a hole 176 in side plate assembly 120, a washer 178,and is threaded into a nut 180 to further the containment of the plates118 and 120.

A bolt 130 is used primarily to secure a hub 124 about which the stick102 and numerous other features will rotate about. In order to make theattachment, bolt 130 passes through an axial bore made through hub 124.Hub 124 is received through an aperture 182 made through side plate 118.A diametrically widened area 184 receives an outwardly extending ridge185 on hub 124. On the other side of side plate 120, an end cap 228closes out the stationary hub. More specifically, an aperture 226 madethrough the side plate assembly 120 receives therethrough adiametrically reduced section 227 of an end cap 228. End cap 228 isthreaded into the stationary hub and secured using bolt 130, a nut 230and cotter pin 232. This enables bolt 130, and cap 228 to secure andsupport all of components 186, 188, 190, 192, 194, 196, 198, 200, 202,204, 206, 208, 210, 212, 214, 216, 218, 220, 222, and 224 together onthe hub 124 such that they are rotatable on the hub 124.

Components 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208,210, 212, 214, 216, 218, 220, 222, and 224 are ring-like devices. First,an RVDT drive spacer 186 is mounted on the hub 124, as are friction disc188, an aperture 190 made through the lower end of a friction leverassembly 192, a friction cam 194, a nested wave spring 196, a frictiondisc 198, a spacer 200, a friction disc 202, a clamp assembly 204, aspacer 206, a first RVDT lever assembly 208, a RVDT drive spacer 210, asecond RVDT lever assembly 212, a RVDT drive spacer 214, a third RVDTlever assembly 216, a RVDT spacer 218, an aperture 220 made through alower portion of the throttle lever assembly 102, a friction disc 222,and a RVDT drive spacer 224.

Drive Levers are Made to Be Independent from Friction Equipment

In operation, the friction lever 192 is adjustable such that the lever34 can be given selective resistance. Although friction lever 192 isrotatable on the hub 124, and is unlinked relative to the other discsmounted on the hub 124, it's rotation is what can create or removefriction. To do this, the lower portion 191 of the friction lever 192has a cam profile that, when rotated, cooperates with a correspondingcam surface existing on friction cam 194 to create expansion of most ofthe discs on the hub 124. Friction cam 194 is rendered relativelystationary by a friction-disk linking bolt 132. Friction-disc linkingbolt 132 is in parallel with bolt 130, but has an axis that is spacedapart therefrom, and is used primarily to secure the friction cam 194and the friction discs 188, 194, 198, 202, and 222 (on opposite side oflever 34) in the system from rotating along with the friction lever 192,or along with the throttle lever 34. More specifically, bolt 132 travelsthrough an aperture 234 made in the side plate 118, an aperture 236 infriction disc 188, aperture 238 made through friction cam 194, aperture240 made through friction disc 198, aperture 242 made through frictiondisc 202, aperture 244 made through friction disc 222, and then issecured on an opposite end by a nut 246. Thus, the friction discs remainstationary against rotation about the hub 124. When lever 192 is movedforward, all of the disk components outside of a friction-exemptingsubsystem (which includes components existing between bearing clamp 204and the inside face of the throttle 34 where is mounted on the hub 124)are compressed.

This arrangement enables the pilot to loosen friction to free throttlemovement, and also to increase friction to avoid the lever fromcreeping, or even lock the lever in place so that the pilot can addressother hand worked controls in the cockpit.

But the excepting subsystem avoids the friction created or released forthe RVDT drive lever assemblies 208, 212, and 216. Bolts 167 and 298extend through throttle lever assembly 102 and the hole sets establishedin each drive lever (holes 171, 173, 175, on the upper portions, andholes 302, 304, and 306 in the lower portions) transfer the rotation ofthe throttle lever 34 to all three of the drive levers 208, 212, and216. Drive levers 208, 212, and 216, during this movement, are exceptedfrom the friction by upper and lower spacers 177 and 308. Spacers 177and 308 extend between this inside surfaces of bearing clamp 204 and theinside surfaces 301 of ring at the bottom of the throttle where it ismounted on the hub 124. When compression (and thus friction) is createdby the friction lever 192 as discussed, the spacers 177 and 308 compressagainst the clamp 204 and the throttle ring surfaces 301. Thus, becausethe spacers 177 and 308 guarantee a defined distance between thethrottle lever assembly 34 (surface 301) and the clamp assembly 204, thethree RVDT lever assemblies 208, 212, and 216 are shielded from thefriction. The defined friction-free space created allows the RVDT leversto act independently from the friction created outside of this definedspace.

RVDT Housing Assembly

Bolts 248, 250 and 252 pass through side plates 118 and 120 and, alongwith spacers 316, 288, 296, 262, 256, 284 and 312 and the correspondingbolts, washers and nuts, secure the RVDT plate assembly to side plate120. Thus, the RVDTs 36, 38, and 40 in place, but are also mechanicallyconnected in an arrangement enabling a breakaway assembly designed toavoid mechanical jams that impede the functionality of the lever-drivenRVDTs 36, 38, and 40.

A bolt 248 initially passes through an aperture 254 made through sidebracket 118, then through a spacer 256, then through an aperture 258formed through a RVDT plate assembly 260. After that, bolt 248 isreceived through a spacer 262, then an aperture 264 formed through sidebracket 120, where it is secured by a washer 266 and nut 268.

A bolt 250 passes through an aperture 282, then through a spacer 284,then through an aperture 286 formed through a mid-lower portion of theRVDT plate assembly 260. Bolt 250 then is received through spacer 288,then through an aperture 290 through the lower end of the side bracket120, and finally is secured using a washer 292 and a nut 294.

A bolt 252 passes through an aperture 310 made through the lower end ofbracket 118, then through a spacer 312, then through an aperture 314made through the bottom of the RVDT plate assembly 260, then through aspacer 316, then through an aperture 318 formed through the bottom ofthe side bracket 120, where it is secured using a washer 320 and a nut322.

The RVDT system subassembly centers around the RVDT plate assembly 122(FIG. 4) which secures the first, second, and third RVDTs 36, 40, and38. First, second, and third RVDTs 36, 40, and 38 each have: (i)cylindrical outside surfaces 324, 326, and 328; (ii) outwardly extendingrims 330, 332, and 334; (iii) passthrough outcropped portions 336, 338,and 340; (iv) and splined shaft 342, 344, and 346, respectively. Theforwardly-extending rod portions 342, 344, and 346 each extend throughcorresponding holes 348, 350, and 352. Portions 336, 338, and 340 eachfit cylindrically inside each hole, and the outwardly extending rims330, 332, and 334 bears against the periphery of each hole the RVDTs arebeing inserted into, and from behind. Overlapping crescent matchingpairs 354 and 356, 360 and 362, 366 and 368, are installed using bolts358, 364, and 370 which are secured into threaded receptacles onto eachside of the RVDT plate assembly 260. The threaded receptacles 372 thatreceive bolts 358 are shown on the exposed side of the RVDT plateassembly 260. It should be understood that a similar arrangement existson the back side of plate 260 for each sets of bolts 364 and 370.

Drive Levers

Lever assemblies 208, 212, and 216 drive levers are rotated along withmovement of the throttle lever 102. To do so, a threaded bolt 167 isinserted through a hole 169 at a location above the axis of rotation ofthe throttle lever about the hub 124. Bolt 167 then passes throughapertures 171, 173, and 175 and is also received into a sleeve-spacer177 (which will form the bearing surface inside the apertures), and athreaded end 165 is then screwed into a receiving nut 179 to link all ofthe lever assemblies together for common rotation upon movement of thethrottle lever 102. This arrangement is made more secure by a bolt 296which has threads 298. The bolt 296 passes through lower aperture 300 onthrottle lever assembly 220, then passes through apertures 302, 304,306, at the bottom of each of lever assemblies 208, 212, and 216, isreceived within sleeve spacer 308 and then the threaded head 298 isscrewed into a receiving nut 311 to secure the bolt 296, completesecurement, and reinforce the common rotation of the lever assemblies208, 212, and 216 from below.

Independent Linkage Systems Between the Drive Levers and the RVDTs

The top of each of the three link arms 270, 272, and 274, shown in FIG.7, are all independently connected about the rotating mechanisms andmechanical connections that actuate RVDTs 36, 38, and 40 respectively.

A first linking arm 270 is attached at the top to an outwardly-extendingdrive arm 372 on drive assembly 212. Aligned eyelets 374 at the upperend of link arm 270 line up with an aperture 376 made though an outerportion of the drive arm, enabling a bolt 378 with a cross bore 379 atits tip to pass through and be secured by a spacer 380, washer 382, andnut 384 when cross pin 386 is installed.

At a lower end of first link arm 270, a similar arrangement includingaligned eyelets 388 line up with an aperture 390 made though an outerend of a driver arm 392. Again this connection is made using a bolt 394with a cross bore 396 at its tip to pass through and be secured by aspacer 398, washer 400, and nut 402 when cross pin 404 is installed.

An inner end 411 of driver arm 392 includes an opening 406 adapted toreceive the splined shaft end 342 of RVDT rod end 38. The end 342 issecured in the opening 406 using a bolt 408 that is received intoaligned crosswise holes 410 and secured by a washer 412 nut 414arrangement.

A second link arm 272 is attached at the top to an outwardly-extendingdrive arm 414 on drive assembly 208. Aligned eyelets 416 at the upperend of link arm 272 line up with an aperture 418 made though an outerportion of the drive arm, enabling a bolt 420 with a cross bore 422 atits tip to pass through and be secured by a spacer 424, washer 426, andnut 428 when cross pin 430 is installed.

At a lower end of the second link arm 272, a similar arrangementincluding aligned eyelets 432 line up with an aperture 434 made thoughan outer end of a driver arm 436. Again this connection is made using abolt 438 with a cross bore 440 at its tip to pass through and be securedby a spacer 442, washer 444, and nut 446 when cross pin 448 isinstalled.

An inner end 449 of driver arm 436 includes an opening 450 in adapted toreceive the splined shaft 344 of RVDT rod end 40. The end 344 is securedin the opening 450 using a bolt 452 that is received into alignedcrosswise holes 454 and secured by a washer 456 nut 458 arrangement.

A third link arm 274 is attached at the top to an outwardly-extendingdrive arm 460 on drive assembly 216. Aligned eyelets 462 at the upperend of link arm 274 line up with an aperture 464 made though an outerportion of the drive arm, enabling a bolt 466 with a cross bore 468 atits tip to pass through and be secured by a spacer 470, washer 472, andnut 474 when cross pin 476 is installed.

At a lower end of the third link arm 274, a similar arrangementincluding aligned eyelets 478 line up with an aperture 480 made thoughan outer end of a driver arm 482. Again, this connection is made using abolt 484 with a cross bore 486 at its tip to pass through and be securedby a spacer 488, washer 490, and nut 492 when cross pin 494 isinstalled.

An inner end 495 of driver arm 482 includes an opening 496 adapted toreceive the splined shaft end 346 of RVDT rod end 36. The end 346 issecured in the opening 496 using a bolt 498 that is received intoaligned crosswise holes 500 and secured by a washer 502 nut 504arrangement.

Rivets Connecting the Driver Halves are Designed to Fail

The drive levers, 208, 212 and 216, in an embodiment, are comprised ofrivet connected lever halves 298, 300, and 302, and opposing halves 304,306, and 308 respectively. As can best be seen in FIGS. 9-12, the softrivets 1000, 1002, 1004, 1006, 1008, and 1010 used to secure togethereach half pairs 298/304, 300/306, and 302/308. FIGS. 9 and 10 show thepairs from different perspectives so both sides can be seen. FIG. 11shows the rivets before they have been flattened to cause the connectionof the pairs. The rivets are designed to shear if one of the lever armsor RVDT's would become jammed. More specifically, the existence of a jamoccurring in the mechanical system between each drive lever and it'srespective RVDT will cause back shear pressure against the rivets. Theshearing of any one rivet, e.g., due to back pressure due to a jam,allows the remaining still-functional levers to rotate about thestationary hub and allowing the throttle quadrant to continue to operatein transmitting two of the three readings from the two unaffected RVDTs.

The specifics regarding each rivet are shown in FIGS. 12 and 13.Although the example chosen for depiction is rivet 1002 used to connecttogether halves 298 and 304 of drive lever 208, it should be understoodthat these cross sections would be substantially the same for all theother rivets (rivets 1000, 1004, 1006, 1008, and 1010). Referring firstto FIG. 12, which is taken from Section 12-12 in FIG. 9, it can be seenthat the rivet includes a head 1020, a shaft 1002, and a through end1024. Those skilled in the art will recognize that a rivet connection iscompleted upon the flattening of the through end against a surface(e.g., surface 1030) on the other side from which it was inserted. Inthe disclosed embodiment, a countersunk area 1026 defined into the half298 is shaped to receive head 1020. Rivet shaft 1002 is received throughaligned holes 1028 bored through both halves 298 and 304. FIG. 13, whichis taken from Section 13-13 in FIG. 9, shows a recessed area 1032 whichis designed to account for the flattened head 1024 which will resultfrom the processed rivet 1000.

Voting Process

A voting process is also disclosed whereby the RVDTs are analyzed foraccuracy. FIG. 14 shows one embodiment as a process 1400. In a firststep 1402 the process starts and then moves on to a query step 1404where it is determined whether the readings from any of RVDTs 36, 38, or40 are inside of a predetermined angular range (e.g., +/−40 degrees) ofrotation from one another. If the three RVDT readings are all within therange, it is a preliminary indication of proper functionality, e.g., anindication that the mechanical and other systems relating to the RVDTsare operating property. If this is the case, the process, inembodiments, uses any one of the three RVDT readings. In someembodiments, the RVDT value of the three is selected at random. In otherembodiments, the RVDT with a middle value is picked. In still furtherembodiments, an averaging is done. Regardless, after step 1406 theprocess then loops back to start 1402 so that the whole process can becontinually repeated.

If in step 1404 one of the RVDT values (for RVDTs 36, 38, and 40) isoutside of the predetermined range (an indication of a mechanical orother problem for that RVDT), the process moves on to a step 1408. Instep 1408 a determination is made as to whether two of the RVDT valuescoming from RVDTs 36, 38, or 40 are inside the predetermined range. Ifso, the tight values are an indication of proper functionality of thetwo, e.g., indicating that the mechanical and other systems supportingthose two RVDTs are operating properly. Thus, the process next, in astep 1410, uses the value of one of the two in-range RVDTs to establishthe lever position. And since the status of the out-of-range RVDT hasbeen called into question, in a next step 1412, a long term warning isgenerated. In some embodiments, this might be a crew-alerting system(CAS) warning, e.g., a white CAS message, which alerts the pilot andothers that the system should be checked, not immediately, but at somemaintenance time in the future. After that, the process loops back tostart 1402.

If, however, in step 1404, there are not two RVDTs inside thepredetermined range, the process moves on to a step 1414 where one ornone of the RVDTs are in the range. When in this situation, theprocessing component will, in a step 1416, go into a default powersetting (e.g., idle if the aircraft is on the ground, cruise if in theair). Also, the processing component transmits a short term warningindicating that the problem should be fixed more immediately (e.g., anamber CAS message). Then the process again loops back to start 1402.

FIG. 15 shows a system environment 1500 wherein the steps shown in FIG.14 are executed by a module 1502 operating on controller 1504 (whichwould be the same as controller 42 shown in FIG. 3). Module 1502 listensto the RVDT outputs, and responsively operates the continually loopedsteps shown in FIG. 14. In embodiments, controller 1504 could be anynumber of computing devices or programmable logic controllers. In thedisclosed embodiment, the controller 42 is a FADEC.

FIG. 16 shows an alternative system environment 1600 in which theprocess described in FIG. 14 might be executed. As can be seen in thefigure, each of RVDTs 36, 38, and 40 are electronically connected into aprocessor 1602. The processor 1602 listens to the RVDT outputs, andcontinuously executes each of the steps, and communicates any necessarycommands to the controller (e.g., FADEC) 1604.

Alternative Embodiments

Other embodiments are possible. For example, a first alternativeembodiment is shown in FIGS. 17-19. These figures show a system where,instead of using the shear rivets in the disc buildup, a series of ballplungers are used that would be located above the drive levers, 1708,1712 and 1716 (see FIG. 17, each of the drive levers would ordinarilyrotate with the throttle stick). Drive levers, 1708, 1712 and 1716 aremostly like the drive levers 208, 212 and 216 already shown, except thatinstead of rivet arrangements, these drive levers include detents at thetop. The detents at the top of each drive lever are each used to receiveball plunger arrangements. One ball plunger arrangement exists for eachdetent atop each of the drive levers. Referring the perspective view ofFIG. 17, the three ball plunger arrangements (not shown) are included ina ball plunger housing 1702. FIG. 18 is a section taken to reveal thedetails for drive lever 1708 (and substantially identical arrangementsexist for each of the other drive levers 1712 and 1716). It can be seenthat a ball plunger 1802 includes a tip 1804 which is received into adetent 1806. The details regarding detent 1806 can be seen in detail inFIG. 19.

Each ball tip (e.g., tip 1804) nests into the detent of each of thedrive levers. The force of the ball plunger into the detent is whatengages the disc-portion of the drive levers to rotate around the hubwhen the throttle lever is rotated, thus ordinarily rotating the RVDT.But when abnormal resistance is encountered (indicative of a mechanicaljam), the spring force of the ball plunger will be overcome, and the tip(e.g., tip 1804) rises up out of the detent (e.g., detent 1806)releasing the drive lever (e.g., drive lever 1708). In case of a RVDTjam, the abnormally high side force on the rotating throttle lever wouldovercome the force in the ball plunger for and create a disengagement.

In order to avoid disengagement upon resistance existing at levels belowwhat would occur with a mechanical jam, the angle existing between walls1902 and 1904 (Ø); and the end force (F) (a/k/a spring force). Thethreshold side force (TSF) is what needs to be determined to preventunwanted disengagement. The determination can be made, given a known Øor after selecting a given ball plunger having a given F value. Thefollowing equation: TSF=F/tan(Ø/2) can thus be used to solve for Ø orfor F, depending on which is the remaining variable. The value for F foreach ball plunger can be uncovered from known data, specifications, ortables for F values for ball plungers. Using a system environmentdescribed herein already as an example, a jammed RVDT would allow thedrive lever to remain stationary while the rest of the assembly wouldstill rotate and operate normally, allowing for the continued functionof the remaining two RVDTs.

A second alternative embodiment involves using frangible links beingcreated for each of the outwardly extending portions 414, 372, and 460,of each of the drive levers 208, 212, and 216. See FIGS. 5 and 7. Theidea is that each of these links would be created such that they wouldbreak whenever a RVDT or linkage jam would occur. The links might bemade to be frangible in a variety of ways. First, a joint can be definedinto the middle each of the RVDT link arms (E.g., first, second andthird linking arms 270, 272, and 274 shown in FIG. 8). The joint wouldbe created as a locations of relative structural weakness in the arms.Thus, upon a jam, the jammed linking arm (one of first, second, andthird linking arms 270, 272, and 274) would break if a jam occurred inthe mechanical system of that arm. Like in other embodiments, the jointsecurement could be made using a rivet or other attached material thatwould break under a predetermined load.

Alternatively, the ends of the RVDT link arms (e.g., and third linkingarms 270, 272, and 274) where the bolts attach to the arms (referring toFIG. 7, end 374 of arm 270, end 416 of arm 272, and end 462 of arm 274)could be made frangible where they join up with the lever arms 372, 414,and 460 respectively. This could be done using some form of frangiblelinks, or using some other means of failure at the arm/lever junction.Alternatively, the drive lever arms themselves (e.g., drive lever arms327, 414, and 460) could be configured as the weak mechanical component,and designed to fail upon the implementation particular torque.

Further still, the opposite ends 388, 432, and 478 of arms 270, 272, and274, respectively, could also be designed to fail. This could also bedone using frangible links.

An additional alternative embodiment is similar to those above, butinstead of using frangible links, the bolts 420, 378, and 466 (see FIG.7) used to make the connections at the end of each of drive levers 208,212, and 216 are designed to fail. For example, they can be created asshear bolts. And the same is true for the connections made by bolts 394,438, and 484. In each instance, a shear bolt would be selected such thatit would shear at a predetermined load.

An additional embodiment might involve making each of the drive leverdisks 212, 216, and 218 force fit onto the outer cylindrical surfaces ofthe hub the drive An option was to somehow make the a slip disc on thehub 124 such that they would slip upon a particular torque.

A further alternative embodiment involves using pressure plates as partof the hub with a new design for the RVDT drive levers. Referring to theembodiment shown in FIGS. 3-16, the RVDT lever attachments would bedesigned with one side having geared teeth that would mate with aspring-loaded plate. The spring-loaded plate would slip when the load onthe RVDT lever attachment approached a designed limit.

A further alternative embodiment works for a RVDT jam or failure onlyand not for a drive linkage failure. This option puts the breakawaymechanism at the RVDT shaft. In the event of an RVDT jam or failure, thedriving linkage arm would break loose from the RVDT splined shaft,allowing the remaining two RVDT's to work. More specifically, acomponent of each of drivers 392, 436, and 482 could be designed tofail. A likely option would be to make the failure at the securementends 411, 449, and 495 (see FIG. 7) at the point of attachment to eachRVDT shaft 344, 346, and 342 (see FIG. 6).

Many different arrangements of the various components depicted, as wellas components not shown, are possible without departing from the spiritand scope of what is claimed herein. Embodiments have been describedwith the intent to be illustrative rather than restrictive. Alternativeembodiments will become apparent to those skilled in the art that do notdepart from what is disclosed. A skilled artisan may develop alternativemeans of implementing the aforementioned improvements without departingfrom what is claimed.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations and are contemplated within the scope of the claims. Notall steps listed in the various figures need be carried out in thespecific order described.

The invention claimed is:
 1. A throttle system comprising: a throttlelever configured to rotate around a hub; a linking system, the linkingsystem mechanically imparting rotation implemented by the throttle leverto an engine control system, the throttle lever rotating about a hub; afriction adjustment lever configured to rotate about the hub, thefriction adjustment lever configured such that movement in a firstdirection of rotation around the hub increases friction experienced bythe throttle lever, and movement in a second direction of rotationaround the hub decreases friction experienced by the throttle; and afriction-exempting subsystem, the subsystem preventing the frictioncreated by the friction adjustment lever to be experienced by thelinking system.
 2. The system of claim 1 wherein: the linking systemincludes at least one rotatable disk which is mechanically linked to androtates with the throttle lever, the rotating disk driving at least onelink to implement rotation into a mechanical-to-electrical conversiondevice, the mechanical-to-electrical conversion device configured to,upon movements of the lever, transmit signals indicating an extent ofdisplacement which are used by the engine control system to increase ordecrease speed.
 3. The system of claim 2 comprising: a first linkingsubsystem including a first rotating disk rotatable about the hub, thefirst disk connected to and driven by the throttle lever to create afirst tangential lever, the first lever driving a first link connectedto rotate a first mechanical-to-electrical conversion device, the firstmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a first signal indicating a first extentof displacement which is usable by the engine control system to increaseor decrease speed; a second linking subsystem comprising a secondrotating disk rotatable about the hub, the second disk connected to anddriven by the throttle lever to create a second tangential lever, thesecond lever driving a second link connected to rotate a secondmechanical-to-electrical conversion device, the secondmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmits a first signal indicating a secondduplicitous extent of displacement which is usable by the engine controlsystem to increase or decrease speed.
 4. The system of claim 3 whereinthe first and second signals are redundant, the engine control systembeing operable on either.
 5. The system of claim 4 wherein thefriction-exempting subsystem exempts the first and second disks frombeing subjected to friction created by the friction lever.
 6. The systemof claim 3 wherein the first and second mechanical-to-electricalconversion devices are Rotary Variable Differential Transformers(RVDTs).
 7. The system of claim 3 comprising: a third linking subsystemincluding a third rotating disk rotatable about the hub, the third diskconnected to and driven by the throttle lever to create a thirdtangential lever, the third lever driving a third link connected torotate a third mechanical-to-electrical conversion device, the thirdmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a third signal indicating a third extentof displacement which is optionally usable by the engine control systemto increase or decrease speed.
 8. The system of claim 7 wherein thethird signal is redundant of the first and second signals, the enginecontrol system being operable on any of the first, second, or thirdsignals.
 9. The system of claim 8 wherein the friction-exemptingsubsystem prevents the third disk from being subjected to frictioncreated by the friction lever.
 10. The system of claim 9 wherein thefirst, second, and third mechanical-to-electrical conversion devices areRotary Variable Differential Transformers (RVDTs).
 11. The system ofclaim 2 wherein the friction adjustment lever creates friction using acam arrangement, the cam arrangement creating compression between thefriction adjustment lever and the throttle lever.
 12. The system ofclaim 11 wherein the rotating disk is maintained in mechanicalindependence from the compression created by the cam arrangement by atleast one spacing device, the spacing device bearing at least some ofthe compression created by the cam arrangement such that the rotatingdisk is unaffected by the friction.
 13. The system of claim 12 whereinthe hub is stationary and is secured between two opposing side plates.14. The system of claim 13 wherein the cam arrangement includes a firstcam portion located on a disk portion at the bottom of the frictionlever, the first cam portion rotating against a second reciprocating camportion located on a relatively stationary friction disk located inbetween the disk portion at the bottom of the friction lever and thethrottle lever.
 15. The system of claim 14 wherein the relativelystationary friction disk is prevented from rotation by a friction-disklinking bolt which is secured through the opposing side plates.
 16. Thesystem of claim 1 wherein the friction adjustment lever is configured toloosen the throttle lever, and secure the throttle lever in place suchthat a pilot does not need to maintain a hand on the throttle lever tomaintain a position.
 17. The system of claim 1 comprising: a throttledisk formed out of a lower portion of the throttle lever to configurethe throttle lever to rotate around the hub; first and second aperturesformed through the throttle disk to receive first and second bolts; thefirst and second bolts passing through first and second sleeves, thesecond and first sleeves comprising the friction-exempting subsystem bybearing compression created by the friction lever, and transmitting thecompression to the throttle disk.
 18. The system of claim 17 comprising:a first linking subsystem and a second linking subsystem in the linkingsystem; the first linking subsystem including a first rotating diskrotatable about the hub, the first disk connected to and driven by thethrottle lever to create a first tangential lever, the first leverdriving a first link connected to rotate a firstmechanical-to-electrical conversion device, the firstmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmit a first signal indicating a first extentof displacement which is usable by the engine control system to increaseor decrease speed; the second linking subsystem comprising a secondrotating disk rotatable about the hub, the second disk connected to anddriven by the throttle lever to create a second tangential lever, thesecond lever driving a second link connected to rotate a secondmechanical-to-electrical conversion device, the secondmechanical-to-electrical conversion device configured to, upon movementsof the throttle lever, transmits a first signal indicating a secondduplicitous extent of displacement which is usable by the engine controlsystem to increase or decrease speed; and a compression disk located onthe hub, the compression disk being connected to the first and secondbolts thus sandwiching the first and second sleeves between thecompression disk and the throttle disk, the first and second disks onthe hub being contained between the compression disk and the throttledisk thus exempting the first and second disks from compression.
 19. Aprocess for securing a throttle in a plurality of positions, comprising:providing a throttle lever on a hub; creating rotation using thethrottle lever; tangentially linking a plurality of redundantengine-driving disks on a hub to the throttle lever; configuring each ofthe engine-driving disks to redundantly link the throttle lever to anengine control system; creating compression on the throttle lever usinga friction lever such that the throttle lever can be secured into theplurality of positions; securing the engine-driving disks between acompression-bearing disk on the hub and the throttle lever; rigidlyspacing apart the compression-bearing disk from the throttle lever tobear the compression created by the friction lever and preventing thefriction created by the friction adjustment lever to be experienced bythe engine-driving disks.
 20. A throttle system comprising: providing athrottle lever on a hub; creating rotation using the throttle lever;tangentially linking a plurality of redundant engine-driving disks on ahub to the throttle lever; configuring each of the engine-driving disksto redundantly link the throttle lever to an engine control system;creating compression on the throttle lever using a friction lever suchthat the throttle lever can be secured into the plurality of positions;securing the engine-driving disks between a compression-bearing disk onthe hub and the throttle lever; rigidly spacing apart thecompression-bearing disk from the throttle lever to bear the compressioncreated by the friction lever and preventing the friction created by thefriction adjustment lever to be experienced by the engine-driving disks.